Aerobic and Anaerobic Bacterial Isolates from Deep-Seated Infections: A Microbiological Study at a Tertiary Care Center in Western Rajasthan

Deep seated pyogenic infections (DSPI) are one of the most common causes of hospitalization resulting in high mortality & morbidity. DSPI are majorly polymicrobial in nature caused by anaerobic and aerobic bacteria. Very few studies have reported anaerobic isolates in DSPI. Thus, this study was formulated to determine both aerobic & anaerobic bacteria from deep seated infections in patients presenting to the institution. Material And Methods: This was a prospective observational study conducted in a tertiary care hospital of Jodhpur from Jan 2020 – Dec 2021. The sample from deep seated infections like aspirated pus, tissue, biopsy material, etc., were collected and processed in both anaerobic and aerobic conditions and the isolates obtained were identified by both conventional and automated methods. Their antibiotic susceptibility was done according to CLSI 2020. Result: Out of the 107 samples collected culture positive was seen in 74.8% (n=80) samples, out of which 85% (n=68) were monomicrobial and 15% (n=12) were polymicrobial. Among these 80 culture positive samples, 92 isolates were isolated; in which aerobic isolates were 92.3% (n=85) and anaerobic were 7.7% (n=7). Among aerobes, most common organism was Klebsiella pneumoniae 35% (n=30). Among the anaerobes, Bacteroides fragilis 71% (n=5) was the predominant isolate. Among the aerobes, ESBL and MBL was detected in 15.7% and 43.7% of total GNBs respectively. Conclusion: This cross-sectional study gives an idea about prevalence of the common aetiology causing deep seated pyogenic infection and also the antibiotic resistance pattern of the isolates in the western part of Rajasthan.